October 2019
Beginner
528 pages
12h 37m
English
Content preview from Beginning Flutter
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13Saving Data with Local Persistence
WHAT YOU WILL LEARN IN THIS CHAPTER
- How to persist saving and reading data locally
- How to structure data by using the JSON file format
- How to create model classes to handle JSON serialization
- How to access local iOS and Android filesystem locations using the path provider package
- How to format dates by using the internationalization package
- How to use the
Futureclass with theshowDatePickerto present a calendar to choose dates - How to use the
Futureclass to save, read, and parse JSON files - How to use the
ListView.separatedconstructor to section records with aDivider - How to use
List().sortto sort journal entries by date - How to use
textInputActionto customize keyboard actions - How to use
FocusNodeandFocusScopewith the keyboardonSubmittedto move the cursor to the next entry'sTextField - How to pass and receive data in a class by using the
Navigator
In this chapter, you'll learn how to persist data—that is, save data on the device's local storage directory—across app launches by using the JSON file format and saving the file to the local iOS and Android filesystem. JavaScript Object Notation (JSON) is a common open‐standard and language‐independent file data format with the benefit of being human‐readable text. Persisting data is a two‐step process; first you use the File class to save and read data, and second, you parse the data from and to a JSON format. You'll create a class to handle saving and reading the data file that uses the ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.